Did you check the docs?

• I have read all the NeMo-Guardrails docs

Is your feature request related to a problem? Please describe.

gemini-embedding-model is in first place on the MTEB benchmarks.
So, I think we need google embedding provider too.

(while I'm doing #1290 , I think it's a good idea to go along with it)

If you don't mind, set me up as an Assignee!, or comment! 🤗

Describe the solution you'd like

Use langchain-google-genai

Describe alternatives you've considered

use google.ai.generativelanguage_v1beta directly

Additional context

No response